The goal is to continue fundamental research into neurochemical mechanisms of psychoactive drugs. Areas that will be a focus of attention during the coming years include the following. Work on the phosphoinositide cycle will be emphasized. Molecular characterization of the IP3 receptor that mediates calcium release will be continued. Isolation of the IP4 receptor, its reconstitution and cloning will be explored. Nitric oxide will be evaluated as a messenger molecule in the action of neurotransmitters, especially excitatory amino acids. Molecular mechanisms of olfaction will be explored. An odorant binding protein which has been cloned and expressed win be evaluated for interactions with potential binding sites in nasal tissue. Alterations in cyclic nucleotide levels in response to odorants will be evaluated. Attempts will be made to isolate peripheral type benzodiazepine receptors and characterize them at a molecular level. Endothelin will be explored as a potential neurotransmitter.